I was at school in the 80s and 90s in the UK and this brings back very fond memories of a highly eccentric Latin teacher I had, who mastered this technique and used it frequently. The other memorable thing about him was how he'd tell us he was going to do some photocopying and head off with no paperwork, only to return 5 minutes later still with no paperwork but smelling of pipe smoke.

Some more modern classrooms had the greenish boards that were a continuous loop that you could roll, but the older ones had black ones that were extremely heavy (maybe slate?). Some of them had a counterbalanced pair on ropes and pulleys in wooden runners, so that when you slid one up the other would come down. I remember in one lesson the ropes snapped and the front-most board came whistling down like a guillotine past the face of the maths teacher and landed with a bang like a gunshot. He was unhurt luckily but was extremely pale and shaken - understandably!